yonkers



March 3, 1964 E. H. YONKERS 3,123,684

CABLE TERMINAL AND SWITCHING DEVICE Filed Nov. 28, 1961 INVENTOR. [DW/WFD H VON/(14 15 BY M W United States Patent 3,123,684 CABLE TERMINAL AND SWITCHING DEVICE Edward H. Yonkers, 757 Bluff St, Glencoe, Ill. Filed Nov. 28, 1961, Ser- No. 155,391 11 Claims. (Cl. 200-48) This invention relates to a cable terminal and switching device, and more particularly, to a switching device in which the switching element can be removed from the switch terminals while the terminals are energized.

As a result of the recent trend toward the increasing use of underground cables to distribute electrical power in expanding residential areas, there is a growing need for safe, compact switch gears, particularly suited to switching and sectionalizing cable terminals at distribution voltage levels. One such terminating device is disclosed in copending United States patent application Serial No. 142,562 filed October 3, 1962 and assigned to the same assignee as the present invention. In conjunction with the use of such terminal devices and underground high voltage cable distribution systems, it is necessary to provide a step-down transformer to develop the low voltages for supply to residences and the like. These transformers are usually of the cabinet type mounted at ground level, and it is desirable that a switch be provided between cable terminals and the transformer terminals. Since it is not feasible to deenergize the distribution system and interrupt services on the entire system when in stalling new equipment on the system or when performing routine maintenance operations, it is desirable that the latter switch be of a type which can be easily and safely installed or removed with the use of a hot line stick while the terminals are energized.

Therefore, it is an object of the present invention to provide a new and improved electrical switching device which can be used in conjunction with a cable terminating device as described in the copending application identified above.

A further object of the present invention is to provide a new and improved electrical switching device in which the switching element can be easily and safely installed or removed with the use of a hot line stick while the switch terminals are energized.

A still further object of the present invention is to provide a new and improved electrical switching device employing a removable switching element which can be easily removed from the switch terminals while still providing a high current capacity switch with accurate alignment and solid engagement between the removable element and the switch terminals.

Briefly, the foregoing and other objects of the present invention are accomplished by providing a switching device having first and second spaced apart terminals electrically connected by a removable switching element. The switching element carries a pivot pin adjacent its lower end seating within an open ended slot in the first terminal, which slot provides a bearing surface for the pivot pin. A retaining spring biases the pivot pin against the bearing surface to pivotally connect the first terminal and the pin of the switching element. The switching element can be removed by moving the pivot pin to deflect the retaining spring means whereupon the pin may be lifted through the open end of the slot. Contact means adjacent the upper end of the switching element removably engages an upper contact on the second terminal to complete the circuit between the terminals when the switching element is closed. A spring clip mounted near the upper end of the switching element receives the pin of a standard hot stick by means of which the switching element can be manipulated during removal or installation without requiring removal of power from the system.

Further objects and advantages of the present invention will become apparent as the following description proceeds, and the features of novelty which characterize the invention will be pointed out with particularity in the claims annexed to and forming a part of this specifications.

For a better understanding of the present invention, reference may be had to the accompanying drawing in which:

FIG. 1 is a front elevational view of a cable terminal and switching device characterized by the features of the present invention with a portion of the lower insulating housing being broken away to show certain details of the cable termination;

FIG. 2 is a side elevational view illustrating the cable terminal and switching device of FIG. 1 with the switching element being shown in broken lines in the position occupied when it is disconnected from the upper terminal and pivoted downwardly to pivot about the lower terminal;

FIG. 3 is an enlarged, fragmentary, sectional view showing the cable terminal of the apparatus illustrated in FIG. 1.

FIG. 4 is a top plan view of the cable terminal shown in FIG. 3; and

FIG. 5 is a side elevational view of a ground switch element as characterized by the features of the present invention.

Referring now to the drawing and first to FIGS. 1 and 2, there is illustrated the upper portion of a cable terminating device of the type disclosed in the above identified copending application to which reference is made for a more detailed description, The device ltil is supported on a bracket 12 which is secured to a wall 14 of an electrical switch box by suitable fasteners 15. The bracket 12 also serves as a grounding means for grounding the lower portion of the terminating device 12 to the switch box or frame on which the device is to be mounted.

The cable termination 1% includes a conventional insulating shell 18 having an upper end wall. 20 provided with a central aperture 22 in order to accommodate a depending hollow stem 24 of a first terminal 25 which is positioned within a recess 28 formed in the upper end of the shell 18. As is shown in FIG. 1, a front portion Ida of the wall of the shell is left open to provide frontal access to the terminal 26.

The terminal 26 is provided with a generally rectangularly shaped body 30 formed integrally with the hollow stem 24,. The lower surface of the body is provided with an integrally formed washer like base 32 and a sealing gasket 34 is interposed between the base and the upper surface of the Wall 20.

In order to securely mount the terminal 26 within the upper recess 28 of the insulating shell 18, the lower end of the hollow stem 24 is externally threaded to receive a nut 36 positioned within the shell 18. A spring washer 38 disposed between the lower surface of the Wall 29 and the nut 36 prevents the nut from threading off of the hollow stem 24 and permits thermal expansion and contraction without subjecting the wall 20 to excessive stresses.

As shown in FIG. 2 a vertical bore extending through the stem 24 and partially through the body 30 accommodates the upper end of an electrical conductor 40 or an extension thereon. In order to retain the cable 40 in the bore 42 a set screw 44 or clamping bolt extends transversely of the bore 42 through a tapped opening 46 defined in the terminal body 30. A metallic collar 48 containing a sealing gasket Sil is positioned adjacent the head of the screw 44. The extreme inner end of the screw 46 seats against the conductor 40 to clamp it in position within the bore 42.

An inclined pin receiving slot 52 in the terminal body 30 receives a pin 54 mounted at the lower end of a re- 'rnovable switching meinberfitl. The slot 52 extends between the side walls of the body 30* and has its upper end opening on the top surface of the body 39 near the rear thereof. The slot extends downwardly and forwardly to terminate in a rounded blind end 52a in the interior of the body 3th The width of the slot 52 is slightly greater than the outer diameter of the pin 54 to provide :a sliding fit therebetween.

A substantially L-shaped leaf spring 56 is secured to the body 30 and has its outer hooked spring end 56c extending into and across a portion of the slot 52. One leg '56:; of the L-shaped spring 56 abuts the front face of the body 3% and is coated with a sealing substance such as a conducting plastic cement or the like to prevent air from leaking into or out of the opening 46 and also to provide good electrical contact between the spring 56 and the body 30. This leg 56a is seated firmly against the front face of the body 30 when the screw 44 is tightened. A second leg 56b of the spring 56 extends through a spring receiving channel 39a (FIG. 4) formed in the upper face of the body 30. The bottom of the channel 3% tapers downwardly near the slot 2 to provide a relieved area accommodating the hooked end 560. The leg 56b may be deflected slightly upwardly away from the top surface of the body when -m upward force is applied to the hooked end 56c by insention or removal of the pin 54. The hooked end 560 of the spring 56 includes a of legs. 57a and 57b cooperating to form a V-shaped end on. the spring 56 to engage the pin 54 when it is seated within the rounded end 5241 of the slot 52. Thus, when the pin 54- is inserted into the slot 52 and is moved downwardly and forwardly therein it engages the leg 57a of the spring 56 thereby deflecting the leg 56b upwardly until the pin 54 slides past the V-shaped spring end 560. 54 moves past the apex of the V-sh-aped spring, the leg 57b biases it into engagement with the blind rounded end 5211 of the slot 52.

The area of suufiace contact between the pin 54 and end 52a of the slot 52 is relatively large and comprises approximately half of the cylindrical surface area of the pin. Also, there is considerable area of surface contact between the leg 57b of the spring 56 and the pin 54. This large area of surface contact provides an electrical connection having a low resistance and high current carrying capacity and at the same time insures a good mechanical pivot connection for the pin 54 in the terminal 26. Preferably, the 54 is coated with a conducting silver or silver alloy to further decrease the resistivity of the electrical connection and increase the current carrying capacity. The relatively long area of engagement bet-ween the pin, the rounded end of the slot 52 and the hooked end 560 of the spring also inhibits lateral movement of the switching element 60 as it is pivoted about the axis of the pin 54.

If it is desired to remove the switching element 60, the pin 54- is moved reanwlardly and upwardly past the hooked end 56c ot the spring 56 and out of the top of the slot 52. In order to facilitate the insertion of the pivot pin 54 into the slot 52, an upwardly extending back stop 62 is secured to the rear face of the body 39 by screws 64 or other fasteners. The upper end of the back stop 62 is provided with a forwardly extending lip 62a which aids in guiding the switching element 60 as it is being connected or disconnected with the terminal 26. The lip 62a is wider than the main portion of the back stop 62 for a purpose which will become apparent from the ensuing description.

The switching element 60 includes, in addition to the pivot pin 54, a U-shaperl arm formed of a bent strip of conducting material and having a pair of parallel, spaced blades 66 joined at their lower ends by the pivot pin 54 and joined at their upper ends by an integrally fiormed end web 6%. The spacing between the parallel blades 66 is slightly larger than the front width of the body As soon as the pin thus permitting the lower end of the arm to span the block but, at the same time, limiting relative lateral movement between these elements. It can be seen from FIGS. 2 and 3 that the pivot pin 54 is positioned adjacent the lower ends of the blades 66 and somewhat to the rear of their longitudinal axes. This positioning of the pin 54 prevents the switching element 60 from being installed improperly upon the terminal 26 since, if the blades 66 were turned to face in the opposite direction from the position shown FIG. 2 the laterally extending lips 62a of the stop 62 would engage the rear edges of the blades 66 to prevent the switching element 60' from being pivoted to the closed position.

Both of the blades are provided near the upper end of the switching element with indentations forming protrusions 66a extending laterally outward from the sides of the blades to form electrical contact surfaces for engaging spring biased contacts 76 of an upper terminal 72 to complete an electrical circuit from the latter terminal to the lower terminal 26. The contacts 70 are in the form of spring arms which firmly engage with the protrusions 66a to provide low resistance electrical contacts and, at the same time, to hold the upper end of the switching element 60 in position after it has been swung to the closed position. The terminal 72 is appropriately mounted in conventional manner on an insulator 74 which, in turn, is preferably supported by the bracket 12.

The upper end of the switching element 60 is also provided with a pair of spaced parallel rings 78 respectively attached to the inside faces of the blades 66. The outer ends of the rings 78 are joined by a spacer pin 80 in order to strengthen the structure. The rings 78 provide means by which the upper end of the switching element 6% may be disconnected from the terminal 72 by the use of a suitable instrument such as an insulated hot stick, the end portion of which is shown in broken lines in FIG. 2 and is identified by the reference numeral 82.

As is best shown in FIG. 1, a hot stick receiving spring clip 84 is positioned between the spaced blade members 66 near the upper end of the switching element 60 immediately below the rings 78. The clip 84 is generally U-shaped and is provided with re-entrant spring arms 84a bent to receive a pin 86 carried at the end of the hot stick 82. The U-shaped clip has its open end facing the upper end or web 68 of the switching element 60.

As is shown in FIG. 2, the switching element 60 is assembled by using a standard hot stick 82 having its headed pin 86 inserted into the spring clip 84 and tightly ernbraced by the re-entrant arms 84a so that the switching element 663 is firmly held on the hot stick and can be safely handled even though the terminals 26 and 72 are energized. The head portion of the pin 86 and the force of the arms 84a on the body of the pin 86 prevent the switching element 69 from falling off of the hot stick 82. With the switching element 60 thus held by the hot stick 82, the pivot pin 54 may be inserted into the open end of the slot 52 by using the stop 62 as a guide. The switching element 6% is then pulled forward by the hot stick 82 to slide the pivot pin 54 forwardly and downwardly within the slot 52 past the hooked end 560 of the spring 56 until the pin is seated against the bearing surface at the end 52a of the slot 52. The hot stick 32 is then pulled further forward to remove the pin 86 from the open end of the spring clip 84 thus disengaging the hot stick 82 from the switching device. After the hot stick is removed from the switching element 60, the latter will lie in the open position shown in broken lines in FIG. 2 and, at this time, the pin 36 of the hot stick 82 can be engaged in the rings '78 and utilized to manually pivot the switching element 60 in a counterclockwise direction as viewed in FIG. 2 until it reaches the closed position there shown in solid lines.

When it is desired to interrupt the circuit during maintenance or installation of new equipment, the pin 86 of the hot stick 82 may be engaged in the rings 78 and the switching element 60 may be withdrawn from the upper terminal 72 by pulling on the hot stick to pivot the element 66 about the lower terminal 26 in a clockwise direction until it is swung to the open position shown in broken lines in FIG. 2. If it is desired to remove the switching element 60 from the lower terminal 26 in order to make certain that the circuit is not recompleted while the aforementioned maintenance or installation is in progress, the hot stick 82 is engaged in the spring clip 84 and the stick is pushed to the left so that the pivot pin 54 is forced rearwardly and upwardly in the slot 52 past the hooked end 560 of the spring 56 until the pin can be lifted out of the top of the slot.

It is highly desirable to have a switching device with a removable switching element of the type described for several reasons. From a safety standpoint, when the switching element 60 is resting in the open position as shown in FIG. 2 in dotted lines, a workman in the surrounding area or housing cabinet might inadvertently touch the switching element while it was energized since the cabinets housing the cable termination do not have sufficient space to permit them to be locked with the switching element swung to the open position on the lower terminal. By removing the switching element 60, the cabinet may be locked to prevent a person from accidentally engaging the hot terminal 26 and also to prevent recompletion of the circuit while work in the system is in progress. By using a removable switching element, the depth of the housing structure or cabinet can be reduced to approximately the thickness of the terminal device alone.

It is also desirable in some instances to insure that the lower terminal 26 is grounded when the switching element 65) has been disconnected and removed from the terminal. For this reason, it is desirable to provide a grounding switch element 60A shown in FIG. 5 which can be temporarily connected to the lower terminal 26 thus keeping the terminal at ground potential in order to provide additional safety for a maintenance man working on the switch device or in the general area.

The grounding switch element 60A is comprised of two parallel switch blades 66A joined at their outer ends by an integrally formed end web 68A and at their inner ends by a pivot pin 54A in a manner similar to the switch element 60. A hot stick receiving spring clip 84A is positioned between the blades 66A near their outer ends for receiving the pin of a hot stick in a similar manner to the spring clip 84-. The outer end web 68A is provided with a lug bolt 88 for attaching one end of a ground cable 96. The other end of the ground cable 90 is connected to any appropriate grounded element in the vicinity. Insertion and removal of the pivot pin MA of the ground switch element 69A into and out of the slot 52 of the lower terminal 26 is similar to the procdure previously described for the switch element 66. Thus, when the ground switch element 60A is connected to the terminal 26, it is then at ground potential and can be safely worked on by a maintenance man.

While there has been shown and described a particular embodiment of the present invention, it will be apparent that various changes and modifications may be made by those skilled in the art without departing from the invention in its broader aspects and it is, therefore, contemplated in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the present invention.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. An electrical switching device for delivering power from a cable to a first terminal spaced from the end of the cable, said device comprising a second terminal vertically spaced from the first terminal, a generally vertically extending switching element for electrically interconnecting said terminals and having a pivot pin adjacent its lower end, said second terminal comprising a rectangularly shaped head having a depending hollow stem adapted to receive the end or" the cable, cable securing means carried by said head for electrically and mechanically securing to said head the end of the cable extending through said hollow stern portion, a stop extending upwardly from said head, said head having defined therein a pivot pin receiving slot extending into said head adjacent said stop, said slot opening on the top surface of said head adjacent said stop and extending downwardly to terminate in a round blind end, retaining means carried upon said head for biasing said pivot pin against the blind end of said slot, said switching element comprising a downwardly facing U-shaped arm having a pair of parallel, vertical, conducting blades joined at their lower ends by said pivot pin, contact means adjacent the upper ends of said blades for electrically and mechanically engaging the first terminal, a pair of spaced ring members respectively attached near the upper ends or" said blades and extending outwardly from said blades in a direction away from said first terminal, said spaced ring members being interconnected at their outer extremities by a pin, and a U-shaped spring clip attached between said blades adjacent said ring members, said spring clip having its open end facing the upper end of said U-shaped arm and adapted to removably receive the pin of a hot stick for assembling and removing the switching element from the second terminal, the switching element being assembled by inserting the pivot pin into said slot and drawing the pivot pin past the retaining means until it engages the blind end of the slot thereupon the switching element may be pivoted until the contact means engages the first terminal, and the switching element being removable from said second terminal by disconnecting the contact means from the first terminal and pivoting the element upon said pivot pin and by then moving the pivot pin past the retaining means and out of the slot.

2. An electrical switching device for delivering power from a cable to a first terminal spaced from the end of the cable, said device comprising a second terminal vertically spaced from the first terminal, a generally vertically extending switching element for electrically interconnecting said terminals and having a pivot pin adjacent its lower end, said second terminal comprising a rectangularly shaped head, cable securing means carried by said head for electrically and mechanically securing the end of the cable to said head, a stop extending upwardly from said head, said head having defined therein a pivot pin receiving slot extending into said head adjacent said stop, said slot opening on the top surface of said head adjacent said stop and extending downwardly to terminate in a round blind end, retaining means carried upon said head for biasing said pivot pin against the blind end of said slot said switching element comprising a downwardly facing U-shaped arm having a pair of parallel, vertical, conducting blades joined at their lower ends by said pivot pin, contact means adjacent the upper ends of said blades for electrically and mechanically engaging the first terminal, switch hook means carried near the upper end of said arm and extending outwardly from said blades in a direction away from said first terminal, and a U-shaped spring clip attached between said blades adjacent said hook means, said spring clip having its open end facing the upper end of said U-shaped arm and adapted to re movably receive the pin of a hot stick for assembling and removing the switching element from the second terminal, the switching element being assembled by inserting the pivot pin into said slot and drawing the pin past the retaining means until it engages the blind end of the slot whereupon the switching element may be pivoted until the contact means engages the first terminal, and the switching element being removable from the second terminal by disconnecting the contact means from the first terminal and pivoting the element upon said pin and by then moving the pin past the retaining means and out of the slot.

3. An electrical switching device for delivering power from a cable to a first terminal spaced from the end of the cable, said device comprising a second terminal vertically spaced from the first terminal, a generally vertically extending switching element for electrically interconnecting said terminals and having a pivot pin adjacent its lower end, said second terminal comprising a rectangularly shaped head having :1 depending hollow stem adapted to receive the end of: the cable, cable securing means carried by said head for electrically and mechanically securing to said head the end of the cable extending through said hollow stem portion, said head having defined therein a pivot pin receiving slot extending into said head from the top surface thereof and extending downwardly to terminate in a round blind end, retaining means carried upon said head for biasing said pivot pin against the blind end of said slot, said switching element comprising a pair of parallel, vertical, conducting blades attached at their lower ends to said pivot pin, contact means provided adjacent the upper ends of said blades for electrically and mechanically engaging the first terminal, l'lOOli means carried near the upper end of said switching element and extending outwardly from said blades in a direction away from said first terminal, and a U-shaped spring clip attached between said blades adjacent said hook means, said spring clip having its open end facing upwardly and adapted to removably receive the pin of a hot stick for assembling and removing the switching element from the lower terminal, the switching element being assembled by inserting the pivot pin into said slot and drawing the pivot pin past the retaining means until it engages the blind end of the slot whereupon the switching element may be pivoted until the contact means engages the first terminal, and the switching element being removable from the second terminal by disconnecting the contact means from the first terminal and pivoting the element upon said pin and by then moving the pivot past the retaining means and out of the slot.

4. An electrical switching device for delivering power from a cable to a first terminal spaced from the end of the cable, said device comprising a second terminal vertically spaced from the first terminal, a generally vertically extending switching element for electrically interconnecting sa-id terminals and having a pivot pin adjacent its lower end, said second terminal comprising a head portion, cable securing means carried by said head portion for electrically and mechanically securing the end of the cable to said head portion, said head portion defining a pivot pin receiving slot extending into said head portion and having a round blind end, retaining means carried upon said head for biasing said pivot pin against the blind end of said slot, said switching element comprising at least one vertical, conducting blade, contact means provided adjacent the upper end of said switching element for electrically and mechanically engaging the first terminal, hook means carried near the upper end of said switching element and extending outwardly from said blade in a direction away from said first terminal, and spring clip carried by said switching element adjacent said hook means, said spring clip having its open end facing upwardly and adapted to removably receive the pin of a hot stick for assembling and removing the switching element from the second terminal, the switching element being assembled by inserting the pivot pin into said slot and drawing the pin past the retaining means until it engages the blind end of the slot whereupon the switching element may be pivoted until the contact means engages the first terminal, and the switching element being removable from the second terminal by disconnecting the contact means from the first terminal and pivoting the element upon said pin and by then moving the pin past the retaining means and out of the slot.

5. An electrical switching device for delivering power from a cable to a first terminal spaced from the end or" the cable, said device comprising a second terminal spaced from the first terminal, a switching element for electrically interconnecting said terminals and having a pivot pin adjacent one end, said second terminal comprising a head, cable securing means for electrically and mechanically securing the end of the cable to said head, said head having defined therein a pivot pin receiving slot extending into said head, retaining means carried upon said head for retaining said pivot pin within said slot, said switching element comprising at least one conducting blade carrying said pivot pin at one end and spanning the space between said terminals, contact means provided adjacent the other end of said blade for electrically and mechanically engaging the first terminal, hook means carried near said other endtof said blade and extending outwardly from said blade in a direction away from said first terminal, and a spring clip attached to said switching element adjacent said hook means for removably receiving the pin of a hot stick for assembling and removing the switching element from the second terminal, the switching element being assembled by inserting the pivot pin into said slot and drawing the pin past the retaining means until it seats within the slot whereupon the switching element is pivoted until the contact means engages the first terminal, and the switching element being removable from the second terminal by disconnecting the contact means from the first terminal and pivoting the element upon said pin and by then moving the pin past the retaining means and out of the slot.

6. An electrical switching device for delivering power from a cable to a first terminal spaced from the end of the cable, said device comprising a second terminal spaced from the first terminal, a switching element for electrically interconnecting said terminals and having a pivot pin adjacent its lower end, said second terminal comprising a head, cable securing means carried by said head for electrically and mechanically securing the end of the cable to said head, said head provided with a pivot pin receiving slot extending into said head, retaining means carried upon said head for retaining said pivot pin within said slot, said switching element comprising a U-shaped arm having a pair of parallel, vertical, conducting blades joined at one end by said pivot pin, contact means adjacent the other end of said arm for electrically and mechanically engaging the first terminal, hook means carried near said other end of said arm and extending outwardly from said blades in a direction away from said first terminal, and a U-shaped spring clip attached between said blades adjacent said ring members, said spring clip having its open end facing said other end of said U-shaped arm and adapted to removably receive the pin of a hot stick for assembling and removing the switching element from the second terminal, the switching element being assembled by inserting the pivot pin into said slot and drawing the pivot pin past the retaining means until it engages the blind end of the slot whereupon the switching element may be pivoted until the contact means engages the first terimnal, and the switching element being removable from said second terminal by disconnecting the contact means from the first terminal and pivoting the element upon said pivot pin and by then moving the pivot pin past the retaining means and out of the slot.

7. An electrical switching device for delivering power from a cable to a first terminal spaced from the end of the cable, said device comprising a second terminal vertically spaced from the first terminal, a generally vertically extending switching element for electrically interconnecting said terminals and having a pivot pin adjacent its lower end, said second terminal comprising a rectangularly shaped head having a depending hollow stem adapted to receive the end of the cable, cable securing means carried by said head for electrically and mechanically securing to said head the end of the cable extending through said hollow stem portion, a stop extending upwardly from said head, said head povided with a pivot pin receiving slot extending into said head adjacent said stop, said slot opening on the top surface of said head adjacent said stop and extending downwardly to terminate in a round blind end, retaining means carried upon said ead for biasing said pivot pin against the blind end of said slot, said switching element comprising a downwardly facing U-shaped arm having a pair of parallel, vertical, conducting blades joined at their lower ends by said pivot pin, and contact means adjacent the upper ends of said blades for electrically and mechanically engaging the first terminal, the switching element being assembled by inserting the pivot pin into said slot and drawing the pivot pin past the retaining means until it engages the blind end of the slot whereupon the switching element may be pivoted until the contact means engages the first terminal, and the switching element being removable from said second terminal by disconnecting the contact means from the first terminal and pivoting the element upon said pivot pin and by then moving the pivot pin past the retaining means and out of the slot.

8. An electrical switching device for delivering power from a cable to a first terminal spaced from the end of the cable, said device comprising a second terminal vertically spaced from the first terminal, a generally vertically extending switching element for electrically interconnecting said terminals and having a pivot pin adjacent its lower end, said second terminal comprising a rectangularly shaped head, cable securing means carried by said head for electrically and mechanically securing the end of the cable to said head, said head provided with a ivot pin receiving slot extending into said head from the top surface thereof, and extending downwardly to terminate in a round blind end, retaining means carried upon said head for biasing said pivot pin against the blind end of said slot, said switching element comprising a downwardly facing U-shaped arm having a pair of parallel, vertical, conducting blades joined at their lower ends by said pivot pin, and contact means adjacent the upper ends of said blades for electrically and mechanically engaging the first terminal, the switching element being assembled by inserting the pivot pin into said slot and drawing the pivot pin past the retaining means until it engages the blind end of the slot whereupon the switching element may be pivoted until the contact means engages the first terminal, and the switching element being removable from said second terminal by disconnecting the contact means from the first terminal and pivoting the element upon said pivot pin and by then moving the pivot pin past the retaining means and out of the slot.

9. An electrical switching device for delivering power from a cable to a first terminal spaced from the end of the cable, said device comprising a second terminal spaced from the first terminal, a removable switching element for electrically interconnecting said terminals and having a pivot pin adjacent one end, said second terminal comprising a head, cable securing means carried by said head for electrically and mechanically securing the end of the cable to said head, said head provided with a pivot pin receiving slot extending into said head terminating in a round blind end, retaining means carried upon said head for biasing said pivot pin against the blind end or said slot, said retaining means including a surface extending longitudinally of said pin for normally maintaining said pin in close interfacial contact with said surface and the blind end of said slot along the length of said pin said switching element comprising at least one conducting blade carrying said pivot pin at one end, and contact means adjacent the other end of said blade for electrically and mechanically engaging the first terminal, the switching element being assembled by inserting the pivot pin into said slot and drawing the pivot pin past the retaining means until it engages the blind end of the slot whereupon the switching element may be pivoted until the contact means engages the first terminal, and the switching element being removable from said second terminal by disconnecting the contact means from the first terminal and pivoting the element upon said pivot pin and by then moving the pivot pin past the retaining means and out of the slot.

10. An electrical switching device for delivering power from a cable to a first terminal spaced from the end of the cable, said device comprising a second terminal spaced from the first terminal, a removable switching element for electrically interconnecting said terminals and having a pivot pin adjacent one end, said second terminal cornprisin a head, cable securing means carried by said head for electrically and mechanically securing the cable to said head, said head provided with a pivot pin receiving slot extending into said head having an end wall, said switching element comprising at least one conducting blade carrying said pivot pin at one end and spanning the space between said terminals, retaining means having a surface normally extending into said slot and positioned with said surface normally engaging said pivot pin to bias said pin against said end wall of said slot and contact means provided adjacent the other end of said blade for electrically and mechanically engaging the first terminal, the switching element being assembled by inserting the pivot pin into said slot and then pivoting it about said pin until the contact means engages the first terminal, and the switching element being removable from the second terminal by first disconnecting the contact means from the first terminal and pivoting the element upon said pin and by then movin the pin out of the slot.

11. An electrical switching device comprising first and second spaced apart terminals, a switching element for electrically interconnecting said terminals, said element having a pivot pin adjacent one end for engagement with said first terminal and contact means adjacent the other end for engagement with said second terminal when said element is in a closed position, slot means defined in said first terminal having an end wall and removably receiving said pivot pin of said switching element and retaining means on said first terminal having a pivot pin engaging surface thereon for normally biasing said pivot pin against said end wall of said slot means said retaining means including a resilient member having a defiectable free end portion defining said pivot pin engaging surface, said pivot pin engaging surface extending along the length of said pivot pin and positioned to normally extend into said slot means.

References Cited in the tile of this patent UNITED STATES PATENTS 975,431 Jackson Nov. 15, 1910 

11. AN ELECTRICAL SWITCHING DEVICE COMPRISING FIRST AND SECOND SPACED APART TERMINALS, A SWITCHING ELEMENT FOR ELECTRICALLY INTERCONNECTING SAID TERMINALS, SAID ELEMENT HAVING A PIVOT PIN ADJACENT ONE END FOR ENGAGEMENT WITH SAID FIRST TERMINAL AND CONTACT MEANS ADJACENT THE OTHER END FOR ENGAGEMENT WITH SAID SECOND TERMINAL WHEN SAID ELEMENT IS IN A CLOSED POSITION, SLOT MEANS DEFINED IN SAID FIRST TERMINAL HAVING AN END WALL AND REMOVABLY RECEIVING SAID PIVOT PIN OF SAID SWITCHING ELEMENT AND RETAINING MEANS ON SAID FIRST TERMINAL HAVING A PIVOT PIN ENGAGING SURFACE THEREON FOR NORMALLY BIASING SAID PIVOT PIN AGAINST SAID END WALL OF SAID SLOT MEANS SAID RETAINING MEANS INCLUDING A RESILIENT MEMBER HAVING A DEFLECTABLE FREE END PORTION DEFINING SAID PIVOT PIN ENGAGING SURFACE, SAID PIVOT PIN ENGAGING SURFACE EXTENDING ALONG THE LENGTH OF SAID PIVOT PIN AND POSITIONED TO NORMALLY EXTEND INTO SAID SLOT MEANS. 